Manufacture of sulfuric acid.



PATENTED MAR. 22, 1904* APPLICATION FILED JUNE 17. 1902.

N0 MODEL.

S E S S E N W W Patented March 22, 1904.

UNITED STATES PATENT OFFICE.

PEDRO G. SALOM, OF PHILADELPHIA, PENNSYLVANIA.

MANUFACTURE OF SULFURIC ACID.

SPECIFICATION forming part of Letters Patent No. 755,247, dated March 22, 1904.

Application filed June 1'7, 1902. Serial No. 112,032. (No specimens) To all w/wm it may concern.-

Be it known that I, PEDROGZ'SALOM, a citi- Zen of the United States, residing at No. 4702 Chester avenue, in the city and county of Philadelphia and State of Pennsylvania, have invented a certain new and useful Process for the Manufacture of Sulfuric Acid, whereof the following is a specification,reference being had to the accompanying drawing.

In said drawing I have represented in vlertital central section an apparatus adapted for the conduct of my process,the main features of the physical structure of said apparatus being those which are set forth in Letters Patent of the United States, No. 669,752, granted to Paul W. Knauf under date of March 12, 1901. This embodiment has been selected for illustration because the present process may conveniently be employed in conjunction with the electrolytic reduction of lead from its sulfid by the use of a similar apparatus, a by-product of said reduction being sulfureted hydrogen gas. Sulfurous acid can readily be obtained by the combustion of this gas, and therefore the process above referred to affords a convenient supply of the initial material which is to be converted into sulfuric acid by the present process.

The underlying principle of operation which is characteristic of the present process is the oxidation of Sulfurous-acid gas in the presence of water by means of "electrolytic action, the current of gas being subjected to progressive treatment in a series of divided receptacles through which it travels. The process is so conducted as to permit the progressive transfer from time to time of the contents ofeach receptacle into the next one of the series and the discharge of the contents of the ultimate receptacle (in which the action has proceeded to the fullest extent) into a receiving vat or tank, the travel of the liquid contents being in the inverse direction to the flow of they gas through the same.

Referring to the drawing, the dish-shaped leaden receptacles A A A &c., are repre sented as arranged in the form of a stack upon a base B, each receptacle having a lateral flange 0;, which is supported on the top rim of the one next below it, an intervening gasket pipe 6. ter, the portions not retained in aqueous soluor washer of rubber b, insulating the receptacles from one another at the region of support.

'Rubbertubes 0 lead from the bottom of each ,fianges a and the tubes being preferably alternately arranged at opposite sides, as shown. A tube d leads from the bottom of the lowest or ultimate receptacle A and is provided with a two-way cock D, by which communication may be established either with the source of Sulfurous-acid gas or with the receiving-tank for the sulfuric acid, neither of which elements is shown. The uppermost receptacle A is in the instance shown merely a cover or cap and is not directly utilized in the process. Atube E leads from the upper portion of the receptacle A, passing through the flange a of the covering-receptacle A, and said tube is arranged to be connected with an air-pump or other source of pressure or with a water-sup' ply, neither ofwhich elements is shown. The lowest receptacle of the stack is electrically connected with the positive pole of a source of electricity and the uppermost receptacle with the negative pole thereof.

The receptacles are filled with water to the levels indicated by f, and when they are thus charged and the electric circuit is established Sulfurous-acid gas is admitted through the The gas bubbles up through the wation ascending through the series of receptacles until the residue, as well as the hydrogen evolved in the process, is discharged at the tube E.

The electrolytic action which occurs in each receptacle sets free oxygen, which combines with the sulfurous acid to form sulfuric acid in solution, and the operation thus proceeds until the maximum quantity of the product has been obtained in the lowest or ultimate receptacle of the stack. Thereupon the cock D is turned, so as to shut off the further supply of Sulfurous-acid gas and to establish communication with the receiving-tank. Pressure is then applied to the uppermost receptacle, for instance, by means of an air-pump connected with the pipe E. This pressure causes the continuous transfer of the contents of the several receptacles, each discharging into the one below it, while the contents of the ultimate one of the series are discharged into the receiving vessel. When a quantity corresponding to the known contents of the lowest receptacle has thus been discharged, the pressure is removed, the uppermost receptacle is filled with water to the proper level, and the supply of sulfurous-acid gas is resumed. This transfer and discharge are repeated as often as the proper saturation is attained in the ultimate receptacle.

It will be observed that the incoming (and therefore the richest) sulfurous-acid-gas current is received in that one of the receptacles Whose contents are most saturated and that as the gas-current travels upward and becomes relatively weaker it is progressively exposed to the weaker and weaker solutions, so that the best results are thus obtained.

Having thus described my invention, I claim 1. The hereinbefore-described process for the manufacture of sulfuric acid, which consists in passing a current of sulfurous-acid gas through a series of independent but communlcatlng receptacles, each of which constitutes an electrolytic cell, and progressively oxidizing said current by electrolytic action, in the presence of water, during the passage of the current through said series, substantially as set forth.

2. The hereinbefore-describedv process for the manufacture of sulfuric acid, which consists in the progressive oxidation of sulfurousacid gas, in the presence of water, in a series of divided but communicating receptacles, by electrolytic action; progressively transferring the contents of each receptacle into the next one of the series; and replenishing the first receptacle and discharging the contents of the ultimate receptacle, from time to time, substantially as described.

In Witness whereof I have hereunto signed my name, with two subscribing witnesses, this 16th day of June, A. D. 1902.

PEDRO Gr. SALOM.

Witnesses:

HENRY F. MORRIS, J AMEs H. BELL. 

